The present invention pertains to a lossless resume capability for peripheral devices. More particularly, the present invention pertains to the storage of data during transitions between suspend and active modes.
With the increasing use of portable computers, a focus has been placed on improving the ability to operate without wired power connections. Therefore, power consumption has become an important concern. Minimizing the amount of energy used by the computer can extend the length of a charge on a computer""s battery. The longer the battery can last between charges, the longer the operator can remain xe2x80x98wireless.xe2x80x99
Alternatively, power usage has become a factor in size reduction of portable computers. The less power a computer needs to operate, the smaller the computer""s battery can be. Also, the less power a computer uses, the less heat created in its operation, and hence, the closer the computer components can be placed to one another, enabling further size reduction of the computer.
Several methods are utilized in the art for minimizing power consumption. One method involves bringing the entire computer system into a state of low power usage (a system xe2x80x98suspendxe2x80x99 mode). The system suspend mode can be set to begin after some pre-determined period of computer inactivity. For example, if the computer receives no operator input for a given period of time, the computer ceases all operations except for those that are necessary for maintaining computer state information, etc. Upon sensing an operator""s input while the computer is in the suspend mode, the computer resumes full operation (returns to a system xe2x80x98activexe2x80x99 mode).
Several problems exist with this form of power management. For example, the system suspend feature can be very disruptive to an operator""s productivity. If the operator is doing work that requires sporadic interactions with the computer system, the operator may often have to wait for the computer to return to the system active mode from the system suspend mode. This transition period can take anywhere from four seconds to a couple of minutes, during which the operator is unable to see his/her work on the screen or interact with the computer. None of the keystrokes or other computer inputs the operator provides will be received or recognized by the computer system during this transition period. They will be lost. The operator is forced to perform a computer input, such as a keystroke, to begin the transition period and wait until the computer system reaches the system active mode before he/she can start to interact with the computer system again.
In the alternative, during normal use by an operator, the computer may never utilize the system suspend feature, thus not reducing power consumption. If the operator consistently interacts with the computer system, the period of inactivity required for the suspend feature may never be reached, preventing power savings or benefit of any kind from this form of power management.
Therefore, there exists a need for an improved method and apparatus for power management that reduces computer power consumption.